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Epigenomics

2,123 bytes added, 21:22, 26 November 2016
Created page with "<p>Epigenomics is the study of the complete set of epigenetic modifications on the genetic material of a cell, known as the epigenome. The field is analogous ..."
<p>Epigenomics&nbsp;is the study of the complete set of&nbsp;epigenetic&nbsp;modifications on the genetic material of a cell, known as the&nbsp;epigenome. The field is analogous to&nbsp;genomics&nbsp;and&nbsp;proteomics, which are the study of the genome and proteome of a cell. Epigenetic modifications are reversible modifications on a cell&rsquo;s DNA or histones that affect gene expression without altering the DNA sequence. Epigenomic maintenance is a continuous process and plays an important role in stability of eukaryotic genomes by taking part in crucial biological mechanisms like DNA repair. Two of the most characterized epigenetic modifications are&nbsp;DNA methylation&nbsp;and&nbsp;histone modification. Epigenetic modifications play an important role in gene expression and regulation, and are involved in numerous cellular processes such as in&nbsp;differentiation/development&nbsp;and&nbsp;tumorigenesis</p>

<p>-DNA metylation : CpG island, 5mC adjacent to G(CpG dinucleotides. by DNA methyltransferase. DNA methylation is stable and heritable &nbsp;&lt;-&gt; DNA de-methylases.</p>

<p>-histone modification :&nbsp;The basic and repeating units of chromatin,&nbsp;nucleosomes, consist of an&nbsp;octamer of histone proteins&nbsp;(H2A, H2B, H3 and H4) and a 146 bp length of DNA wrapped around it.&nbsp;Chromatin remodeling occurs via&nbsp;post-translational modifications&nbsp;of the&nbsp;N-terminal tails of core histone proteins&nbsp;(Russell 2010 p.&nbsp;529-30). The collective set of histone modifications in a given cell is known as the&nbsp;histone code. Many different types of histone modification are known, including:&nbsp;acetylation,&nbsp;methylation,&nbsp;phosphorylation,&nbsp;ubiquitination,&nbsp;SUMOylation,&nbsp;ADP-ribosylation,&nbsp;deamination&nbsp;and&nbsp;proline isomerization; acetylation, methylation, phosphorylation and ubiquitination have been implicated in gene activation whereas methylation, ubiquitination, SUMOylation, deamination and proline isomerization have been implicated in gene repression.</p>

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<p>https://en.wikipedia.org/wiki/Epigenomics</p>
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